Thanks for the offer, I appreciate it, but actually there is no wear on the cover, the photo may just make it look that way. Fortunately, they use a plastic sleeve/spacer over the shaft, and that is what would rub on the case. I do have around .010" of end play in it which I could use a shim for to reduce the next time I have the cover off (which I hope will not be for a very long time) if I wanted to. The shaft od is around 20 mm. I haven't looked at the machine shims at the hardware store yet but they may have something close. If they don't, not maybe a trans shim off some motorcycle will fit.